Photographic subbing materials

ABSTRACT

Solvent soluble carboxylated polyester subbing materials for photographic elements. An organic solvent soluble polyester is carboxylated by treatment, during the latter stages of polymerization, with an organic dianhydride to produce an organic solvent soluble carboxylated polyester. The solvent soluble carboxylated polyester is effectively used in subbing compositions, desirably containing attack solvent, e.g., coated onto a polyester photographic film support and has excellent adhesion both to support and to conventional gelatin-cellulose ester subbing layers used to adhere a gelatino silver halide emulsion to the support.

United States Patent Jacoby et al. [4 1 Apr. 25, 1972 54] PHOTOGRAPHICSUBBING 3,434,840 3/1969 De Keyser et al ..96/87 MATERIALS 3,459,5848/l969 Caldwell ....260/75 X 3,460,982 8/1969 Appelbaum 96/87 [72]Inventors: Frederick J. Jacoby; Frederick L. Hamb; 3,495,984 2/1970vanpoecke Lewis C. Trent, all of Rochester, NY. [73] Assignee: EastmanKodak Company, Rochester, "W Emwner-Joh" coolkaslan 7 AssistantExaminer-Joseph C. Gll

AtI0rney-Walter O. Hodson and Dwight J Holter [22] Filed: Oct. 9, 1969[52] U.S. Cl. ..96/87, 260/75 R, 260/76, 260/33.4 R

[51] Int. Cl ..G03c 1/80 [58] Field of Search ..46/87; 260/75 R, 75 T,76, 260/33.4 R

[56] References Cited UNITED STATES PATENTS 3,360,543 12/1967 Hoy..260/76 X 3,397,254 8/1968 Wynstra et al. ..260/75 X [57] ABSTRACTSolvent soluble carboxylated polyester subbing materials forphotographic elements. An organic solvent soluble polyester iscarboxylated by treatment, during the latter stages of polymerization,with an organic dianhydride to produce an organic solvent solublecarboxylated polyester. The solvent soluble carboxylated polyester iseffectively used in subbing compositions, desirably containing attacksolvent, e.g., coated onto a polyester photographic film support and hasexcellent adhesion both to support and to conventional gelatin-celluloseester subbing layers used to adhere a gelatino silver halide emulsion tothe support.

2 Claims, No Drawings PHOTOGRAPHIC SUBBING MATERIALS This inventionrelates to compositions for rendering gelatinous compositions adherentto polyester supports. in one of its aspects this invention relates tophotographic supports and to the preparation of materials useful inphotographic supports. ln another of its aspects this invention re-.lates to photographic elements and methods for the preparation ofphotographic elements.

it is known in the art to coat gelatino silver halide emulsions onvarious supports including film supports. Plastic film supports, duetotheir dimensional stability, flexibility, clarity, and other physicalproperties constitute a class of known film supports. Of the manyplastic film supports suitable in photography, polyesters such aspolyethylene terephthalate are excellent. However, it is generallydifficult to adhere a hydrophilic gelatin-containing emulsion on ahydrophobic polyester support. In the past there have been severalattempts to overcome this problem among the most successful of which isthe interposition of one or more subbing layers between the polyestersupport and the gelatin-containing emulsion.

Although solvent solutions of polymeric compounds have been reported,these subbing layers have normally involved an aqueous dispersion of thesubbing compositions which is applied to the support material. Even withrelative success of prior products the seemingly ever increasing demandfor new and better products at reasonable cost has stimulated extendedresearch to find subbing compositions which can be utilized moreeffectively and efficiently.

We have found that carboxylated, organic solvent soluble polyesters areprovided by reacting, under polymerizing conditions, an organic diacidconstituent with a glycol constituent and, optionally, at least onemodifying agent selected from the group consisting of organic diacidsand diols, said modifying agent being different from said diacidconstituent and said glycol constituent, to destroy the regularity ofthe polymer molecule, to produce an organic solvent soluble polyesterpolymer, and, during the latter stages of the process, introducing up tomole percent, based on the total amount of said acid constituent andacid modifying agent, of an organic dianhydride, to produce acarboxylated, organic solvent soluble polyester.

Organic solvent solutions of such dianhydride modified polyestersadvantageously also containing an effective amount of polyester attackagent are advantageously utilized as subbing compositions, whichtenaciously adhere gelatinous layers to polyester supports. Photographicelements prepared using such dianhydride modified polyester subbingcompositions desirably comprise a polyester support, a gelatin-celluloseester (desirably nitrate) photographic subbing layer, a gelatino-silverhalide emulsion layer on said gelatin-cellulose ester layer, and thedianhydride modified (carboxylated) organic solvent-soluble polyestersubbing layer bonding said gelatin-cellulose ester'layer to saidpolyester support, said carboxylated polyester being thereaction productof an organic solvent soluble polyester and up to 10 mole percent, basedon the amount of acid constituents, of an organic dianhydride.

According to one advantageous embodiment of the present invention theorganic solvent soluble polyester is the polymeric reaction product ofan organic diacid and a glycol having an average molecular weight of atleast about 6,000 to about 25,000 and desirably from about 10,000 to25,000.

The acid constituent can be any dibasic organic acid capable ofpolymerization with a linear glycol having from two to six carbon atoms.Suitable dibasic acids include the aliphatic, cycloaliphatic andaromatic types such as adipic acid, suberic acid, sebacic acid, andother aliphatic dicarboxylic acids, 1,3- cyclohexanedicarboxylic acid,l,4-cyclohexanedicarboxylic acid and other alicyclic acids, isophthalicacid, terephthalic acid, 2,o-naphthalenedicarboxylic acid, and othersingle or fused ring aromatic diaeids. Polyesters made from thesediacids are made by either direct esterification or transesterificationtechniques and, in the latter instance, lower alkyl diesters of thediacids are utilized. The methyl and ethyl diesters are preferred. inany event, the terms acids," "diacids, and

the like as used herein to define the polyester constituent which iscondensed with the glycol, includes lower alkyl diesters of the diacidsas well as the acids per se.

The glycol constituent making up the polyester is desirably a linearaliphatic glycol having from two to six carbon atoms. Ethylene glycol isespecially useful.

The choice of some glycol-acid combinations for preparation of thepolyesters, according to one embodiment of the present invention, suchas ethylene glycol and isophthalic acid result in polymers which aresoluble in methylene chloride and can be employed without furthermodification. However, some acid-glycol combinations can result inpolyesters which have less than desired solubility. In such situationsit is advantageous to incorporate one or more modifying agents whichdestroy the regularity of the polymer molecule. According to a highlyadvantageous embodiment of the present invention, even in thoseinstances where the choice of acid and glycol is such that the polyesterwould be sufficiently soluble in methylene chloride, the resultingpolyester can be made even more soluble by the incorporation of suchmodifying agents. The modifying agent is desirably selected from organicdiacids and diols. The amount of modifying agent can vary widely butwill generally be not more than 50 mole percent of the total acidconstituents in the case of diacid modifiers and not more than 50 molepercent in the total glycol constituents in the case of diol modifiers.The minimum amount of the modifiers will vary widely but will in generalbe an amount sufficient to achieve a polyester which is soluble inmethylene chloride. A practical minimum is about 10 mole percent basedon the total amount of glycol or acid as the case may be.

The diol modifier is an organic diol copolymerizable with the otherpolymer constituents and different in structure from the main glycolconstituent. Suitable diol modifiers include aliphatic glycols includingboth straight chain glycols preferably of three to 10 carbon atoms andbranched chain glycols preferably of five to 15 carbon atoms such asneopentyl glycol and 2-n-butyl-Z-ethyl-propane-l,3-diol; alicyclic diolscontaining from four to 20 carbon atoms such as l,4-cyelohexanedimethanol, 2,2,4,4-tetramethylcyclobutane-1,3-

diol, and 2,Z-norbornandedimethanol; hydroxy terminated polyethers oflow molecular weight such as about 200 to about 2,000; and hydroxyterminated compounds with other internal functional groups such as acarbonyl group or an ester group or the anhydride group of a compoundsuch as hydroxypivalyl hydroxypivalate.

The acid modifier is an organic dicarboxylic acid copolymerizable withthe other polymer constituents and different in structure from the mainacid constituent. Suitable acids include linear and branched aliphaticacids of any number of carbon atoms such as sebacic acid anddi-n-butylmalonic acid; alicyclic diacids such as l,3- orl,4-cyclohexanedicarboxylic acid; aromatic acids having a single ringsuch as terephthalic and isophthalic acid; or fused rings such as 2,6-naphthalene-dicarboxylic acid; and substituted aromatic acids such ashalogen substituted aromatics such as 2,5- dichloroterephthalic acid.

While in general, only a single modifier molecule is introduced into thepolymer backbone, it is, of course, possible to introduce more than onediol modifier or acid modifier and it is further possible to introduceone or more diol modifiers together with one or more acid modifiers. Thefunction of the modifier is to increase solvent solubility or to renderthe polymer appreciably soluble in methylene chloride. In order toachieve this, it is sufficient to introduce a single modifier and thisis preferred since fewer reagents are used. However, the use of severalmodifiers does not in any way impair solubility and the use of aplurality of modifiers is thus within the scope of the invention.

Carboxylated polymers are prepared according to the invention byintroducing an organic dianhydride reactant toward the end of thepolymerization of the organic solventsoluble polyester described above.The carboxylated polyesters are prepared by polymerizing the basic acidand glycol constituents and the optional modifying constituent by knowntechniques and then adding the dianhydride during the latter stages ofthe process. During the latter stages, the polymer molecular weightpreferably appears to lie in the range l0,00025,000.

Although the polyesters can be formed by any standard melt techniques,one advantageous method is to prepare the carboxylated polyesters bypolymerizing the basic acid constituent and all but a small portion ofone or the other or both the basic glycol and the optional modifyingconstituent, adding the remaining glycol to the reaction mixture duringthe latter stages of the reaction, and finally adding the dianhydridebefore termination of the reaction. The glycolyzing step in thisprocedure causes the formation of lower molecular weight polymers andinsures their termination prior to addition of the dianhydride byhydroxyl groups. In general, the presence of hydroxy termination isensured by using a molar excess of glycol to diacid of preferably atleast 25 to 50 mole percent.

The dianhydride as mentioned is added in the late stages of thepolymerization. In an exceptionally advantageous embodiment of theinvention, the dianhydride is added to the desired polyester melt attemperatures in the range 400475 F. Higher temperatures lead toundesireable crosslinking while at lower temperatures the viscosity ofthe polymer is often such that it is difficult to assure adequatemixing. The time of mixing from first addition of dianhydride, formaximum efficiency, is usually from about to about minutes. Longer timestend to result in crosslinked products and shorter times occasionallyresult in unsatisfactory mixing.

The dianhydrides utilized according to the present invention can varywidely in structure but are advantageously monomeric organicdianhydrides desirably having the formula:

wherein R is a tetravalent organic radical containing from about four toabout 30 carbon atoms and advantageously at least one linkage and/or anoxygen atom. For example, R can be a tetravalent organic radical whichcontains: monocyclic aromatic hydrocarbon moieties, such as in 3,4,3,4-benzephenonetetracarboxylic dianhydride, and especially pyromelliticdianhydride; fused polycyclic, e.g., bicyclic, aromatic hydrocarbonmoieties, such as 1,4,51,8- naphthalenetetracarboxylic dianhydride;saturated carbocyclic moieties, such as inl,2,3,4-cyclopentanetetracarboxylic dianhydride; heterocyclic moieties,e.g., having five to seven ring atoms, such as in2,3,4,5-tetrahydrofurantetracarboxylic dianhydride; and cyclic moieties,e.g., hydrocarbyl moieties having five to 12 C atoms, such as in thedimaleic anhydride adduct of myrcene. Advantageously, the dianhydride isselected from the group consisting of 3,4,3',4'-benzephenonetetracarboxylic dianhydride, the dimaleic anhydride additionproduct of myrcene and especially pyromellitic anhydride.

The reacted moiety from the dianhydride desirably is present in thecarboxylated polyester in at least 1 mole percent and up to about 15mole percent, with about 4 mole per cent up to about 12 being apreferred range.

The following Examples are included for a further understanding of theinvention.

EXAMPLE 1 Poly(ethylene 2-n-Butyl-2-ethyl'1,3-trimethylene Terephthalate70:30) with 10 Percent Pyromellitic Dianhydride A mixture of 194 g. (1.0mole) of dimethyl terephthalate. 83 g. (0.516 moles) of2-n-butyl-2-ethylpropane-1 ,3-diol. and 74.5 g. (1.20 moles) of ethyleneglycol is placed in a one liter three-neck stainless steel resin flask.The mixture (ester: total glycol 1:1.7) is treated with 0.066 g. of zincacetate dihydrate and 0.084 g. of antimony (lll) oxide. The temperatureis then maintained at l-225 C. until the theoretical amount of methanolformed in the ester exchange has distilled out (130 minutes). Thedistillation column is replaced by a solid receiver and a vacuum of1.5-2.0 mm. is maintained for a 2l5-minute period while the temperatureis slowly increased from 225 to 270 C. Heating is discontinued, thereaction flask is opened to an inert nitrogen atmosphere, and 21.8 g.(0.1 mole) of powdered pyromellitic dianhydride is added to the reactionmixture and stirred in the nitrogen atmosphere at 230 to 250 C. for 10minutes. The dianhydride dissolves during this time. Upon cooling, theproduct is a clear, tough polyester having an inherent viscosity of0.59. The inherent viscosity in this Example and reported elsewhereherein is measured in ml. of a 1:1 phenol:chlorobenzene solvent mixtureat 25 C. and employing 0.25 g. of polymer. The polymer is readilysoluble in methylene chloride from which clear film can be cast.

EXAMPLE 2 Poly(ethylene 2-n-Butyl-2-ethyl-l ,3-trimethyleneTerephthalate 70:30) with 2.5 Percent Pyromellitic Dianhydride Reactionwas performed just as in Example 1, except 5.5 g. (0.025 mole) ofpyromellitic dianhydride is added during the latter stages of thereaction. lnherent viscosity of the methylene chloride-soluble polymeris 0.63.

EXAMPLE 3 Poly(ethylene 2-n-Butyl-2-ethyl-1,3-trimethylene Terephthalate70:30) with 5 Percent Pyromellitic Dianhydride A mixture of 388 g. (2.0moles) of dimethyl terephthalate, 165 g. (1.032 moles) of2-n-butyl-2-ethylpropane-1,3-diol, and 149 g. (2.41 moles) of ethyleneglycol is placed in a l-liter three-neck stainless steel resin flask.The mixture (ester: total glycol 2:3.4) is treated with 0.132 g. of zincacetate dihydrate and 0.166 g. of antimony (lll) oxide. The temperatureis then maintained at l95-225 C. until the theoretical amount ofmethanol formed in the ester exchange has distilled out minutes). Thedistillation column is replaced by a solid receiver and a vacuum of1.5-2.0 mm. is maintained for a 215-minute period while the temperatureis slowly increased from 225 to 270 C. Heating is discontinued, thereaction flask is opened to an inert nitrogen atmosphere, and l 1.54 g.(0.072 mole) of 2-n-butyl-2-ethylpropane-l,3-dio1 is added. This isallowed to react for 4 minutes at a temperature of 250 C. and isaccompanied by a decrease in melt viscosity. At this time, 21.8 g. (0.1mole) of powdered pyromellitic dianhydride is added to the reactionmixture and stirred in the nitrogen atmosphere at 230 to 250 C. for 10minutes. The dianhydride dissolves during this time. Upon cooling, theproduct is a clear, tough polyester having an inherent viscosity of0.42. The polymer is readily soluble in methylene chloride from whichclear film can be cast.

EXAMPLE 4 Poly(ethylene 2,2-Dimethyltrimethylene Terephthalate 70:30)with 2.5 Percent Pyromellitic Dianhydride Neopentyl glycol (0.3 molepercent of total glycol feed) is used to replace the2-n-butyl-2-ethylpropane-l,3-diol in Example l. The reaction is allowedto proceed as in Example 1 and 2.5 mole percent pyromellitic dianhydrideis added after a high molecular weight of from l0,000 25,000 has beenobtained. Inherent viscosity is 0.66.

EXAMPLE 5 Poly(ethylene Terephthalate lsophthalate 70:30) with 2.5Percent Pyromellitic Dianhydride A mixture of 272 g. (1.4 moles) ofdimethyl terephthalate, 116 g. (0.6 mole) of dimethyl isophthalate, and213 g. (3.44 moles) of ethylene glycol is treated with 0.132 g. ofZn(OAc)- -2b8H O and 0.166 g. of Sb O. The polymer is prepared as in thepreceeding Examples requiring 90 minutes at l90220 C. for the firststage and allowing the second stage 55 minutes at 1.0 mm. with thetemperature rising to 285 C. the dianhydride (2.5 mole percent) isstirred with the polymer under nitrogen at 245 C. for minutes. Theinherent viscosity is 0.66 and the polymer is soluble in methylenechloride.

Example 6 Poly(ethylene 2-n-Butyl-2-ethyl-l ,3-trimethylene lsophthalate80:20) with 2.5 Percent Pyromellitic Dianhydride A mixture of 388 g.(2.0 moles) of dimethyl isophthalate, 198 g. (3.2 moles) ofcthyleneglycol, and 128 g. (0.8 mole) of 2-n-butyl-2-ethylpropane-1,3-diol istreated with 0.13 g. Zn(OAc)2-2b8H3O and 0.17 g. 51); ,03. The polymeris prepared in the usual fashion with the first stage requiring 110minutes at l95225 C. and the second stage consuming 215 minutes at 1.0mm. with the temperature rising to 275 C. Heating is discontinued andpyromellitic dianhydride (2.5 mole percent) is stirred with the polymerunder nitrogen at 245-255 C. for 10 minutes. The inherent viscosity is0.59 and the polymer is soluble in methylene chloride.

EXAMPLE 7 Poly(ethylene lsophthalate) with 2.5 Percent PyromelliticDianhydride Polymer is prepared as in previous examples using:

388 (2.0 moles) dimethyl isophthalate,

248 (4.0 moles) ethylene glycol,

0.13 g. (ZnOAc) -2H O, and

0.17 g. Sb O After the polymer attains a satisfactorily high molecularweight, 10.9 g. (2.5 mole percent) of pyromellitic dianhydride is added.The final product has an inherent viscosity of 0.63 and is soluble inmethylene chloride.

EXAMPLE 8 Poly( ethylene 2-n-Butyl-2-ethyl-1,3-trimethyleneNaphthalene-2,6-dicarboxylate 80:20) with 2.5 Percent PyromelliticDianhydride A mixture of 305 g. (1.25 moles) of dimethyl 2,6-naphthalene-dicarboxylate, 107 g. (1.72 moles) of ethylene glycol, and69 g. (0.43 mole) of 2-nbutyl-2-ethylpropane-1,3- diol is treated with0.083 g. of Zn(OAc) '2H O and 0.10 g. of Sb O The polymer is prepared asabove, the first stage requiring 180 minutes at l95225 C. and the secondstage 60 minutes at 1.0 mm. with the temperature rising to 270 C.Heating is discontinued, and the dianhydride (2.5 mole percent) isstirred with the polymer under nitrogen at 240 C. for 10 minutes. Theinherent viscosity is 0.53 and the polymer is completely soluble inmethylene chloride.

The polyesters listed in Table 1 below are made in a manner similar tothe foregoing examples and are soluble in methylene chloride.

TABLE 1 Example Polymer Ingredients 9 ethylene glycol: 1,6-hexane diol(75 :25) terephthalic acid 2.5 mole 7r pyromellitic dianhydride ethyleneglycol: 2-n-butyl-2- ethylpropanel ,3-diol (70:30) terephthalic acid 10mole pyromellitic dianhydride ethylene glycol: neo pentyl glycol (40:60)terephthalic acid 2.5 mole pyromellitic dianhydride ethylene glycol:2,2,4,4-

tetramethyl-l ,3-cyclobutane diol (65:35) terephthalic acid 2.5 mole 7cpyromellitic dianhydride ethylene glycol: 1,4-cyclohexane dimethanol(65:35) terephthalic acid 2.5 mole 7c pyromellitic dianhydride ethyleneglycol: 3-methyl-2,2-

norbornanedimethanol (75:25) terephthalic acid 10% pyromelliticdianhydride ethylene glycol: polyethylene glycol of M.W. 400 (75:25)terephthalic acid 2.5 mole 7: pyromellitic dianhydride ethylene glycol:polyethylene glycol of M.W. 1000 (75:25) terephthalic acid 2.5 mole 7:pyromellitic dianhydride ethylene glycol: hydroxypivalyl hydroxypivalate(75:25) terephthalic acid 2.5 mole 7c pyromellitic dianhydride ethyleneglycol terephthalic acid:

sebacid acid (60:40) 2.5 mole 7c pyromellitic dianhydride ethyleneglycol terephthalic acid: 1,3-cyclohexanedicarboxylic acid (55:45) 2.5mole 7c pyromellitic dianhydride ethylene glycol terephthalic acid:dichloroterephthalic acid (70:30) 2.5 mole 7c pyromellitic dianhydrideethylene glycol terephthalic acid: 2,6naphthylene dicarboxylic acid(60:40) 2.5 mole 7: pyromellitic dianhydride ethylene glycol: neopentylglycol 65 :35) 2,6-naphthylenedicarboxylic acid 2.5 mole 7r pyromelliticdianhydride ethylene glycol: neopentyl glycol (70:30) adipic acid 2.5mole 7c pyromellitic dianhydride ethylene glycol:2-n-butyl-2-ethylpropane-1,3-diol (70:30) l,4-cyclohexanedicarboxylicacid 2.5 mole 7: pyromellitic dianhydride EXAMPLES 2S28 A series ofpolyesters are made as in Example 1 except that differing amounts ofpyromellitic anhydride are employed and the polyesters are solutioncoated on a fully oriented polyethylene terephthalate film support froma solution containing 1 percent polymer, 3 percent resorcinol, 20percent cyclohexanone, and about 76 percent methylene chloride and airdried at 240 to 250 F. the coating is then tested for adhesion afterfurther coating thereon. first a standard mixed gelatin-cellulosenitrate subbing layer and then a standard gelatinous emulsion. The tapetest is a standard test for adhesion whereby a strip of transparentpressure sensitive adhesive tape- (Scotch" tape) is applied across atorn edge of the coated material and then ripped free. The tape willcarry along large amounts of emulsion from material having poor adhesionbut little, if any, from material having very good adhesion. The wet anddry cycle test involves passing the coated material to be tested througha cycle of heating, wetting, and drying hundreds of times. This is avery severe test. The percent failure is an indication of the lighttransmission through the element or the amount of emulsion removed fromthe support. A zero percent failure would indicate no emulsion removed,etc. The results are shown in Table II.

EXAMPLES 29-31 A series of polyesters is made as in Example 1 using 30ethylene glycol and 2-n-butyl-2-ethyl-l,3-propanediol in a ratio of70:30, dimethyl terephthalate, and 4 mole percent of various anhydridesas shown in Table Ill. The polyesters are coated and tested as inExamples 25-28. They show good adhesion, but noticeably less than isobtained with polymers containing the same amount of pyromellitic acid.

TABLE III EXAMPLE 32 One percent of carboxylated polyester of Example 4is dissolved in a mixture of 3 percent resorcinol, percent cyclohexanoneand 74 percent methylene chloride. A trace amount (0.1 percent) ofNigrosine dye is present to facilitate the identification of the site ofadhesion failure. This solution is then applied to fully orientedpolyethylene terephthalate Estar") support and air dried at 240 to 250+F. Over this carboxylated polyester coat is applied a mixedgelatin-cellulose nitrate sub. The organic solvent mixture for thisgelatin-cellulose nitrate sub is 20 percent acetone, 45 percent ethylenechloride, 2.5 percent water, and 30.5 percent methyl alcohol. This subwas then dried at 250 to 260 F. The subbed element is then coated with aconventional gelatino silver halide emulsion and adhesion is tested asbefore. The emulsion coated support rates very good in the tape test andshows about 8 percent failure in the 6-hour wet and dry cycle adhesiontest.

A control sample, a commercial photographic element having celluloseacetate support, cellulose nitrate-gelatin subbing layer, gelatinosilver halide emulsion is tested in a similar manner and shows about 2percent failure in the wet and dry adhesion test and rates very good inthe tape test.

EXAMPLE 33 Example 32 is followed except that 6 percent resorcinol isused instead of 3 percent resorcinol. The resultant coated emulsionrates very good in the tape test and shows only about 2 percent failurein the wet and dry adhesion test.

EXAMPLE 34 The procedure according to Example 33 is followed except thatthe polymer is a poly(ethylene neopentylene terephthalate 40160)modified with 10 mole percent pyromellitic dianhydride. The resultingemulsion coated support rates excellent in the tape test and shows onlyabout 1 percent failure on the 6-hour wet and dry cycle adhesion test.

EXAMPLE 35 The procedure according to Example 34 is followed except thatabout 3 percent l-naphthol is utilized as an adhesion promoter in placeof the 6 percent resorcinol. The resulting emulsion coated support ratesfair in the tape test and shows 3 percent failure in the wet and dryadhesion test.

EXAMPLE 36 The procedure according to Example 34 is followed except that20 percent acetone is substituted for the 20 percent cyclohexanone. Theresultant emulsion coated support rates excellent in the tape test andshows 3 percent failure in the wet and dry adhesion test.

EXAMPLE 37 The procedure according to Example 34 is followed except thata gelatin subbing is used instead of the gelatin-cellulose nitratemixture. The resultant emulsion coated support rates fair in the tapetest and shows 3 percent failure in the wet ad dry cycle adhesion test.

EXAMPLE 38 The procedure according to Example 34 is followed except that6 percent catechol is substituted for the 6 percent resorcinol. Theresultant emulsion coated support rates fair to poor on the tape testand shows 1 1 percent failure on the wet and dry cycle adhesion test.

The polyester substrate to which the carboxylated polyester adheres isan oriented polyester film such as a polymer of terephthalic orisophthalic acid or their mixtures or cyclohexanedicarboxylic acid withethylene glycol, l,4-cyclohexanedimethanol and the like. in general, thepolyester comprises the linear polymer reaction product of an organicdiacid and an organic diol capable of being fabricated into tough film.

The photographic emulsion carried on the polyester support is of theconventional gelatin containing type wherein silver halide or otherlight sensitive compound is distributed in a binder ofgelatin or gelatinin admixture with another compatible binder such as gelatin derivatives,polyvinyl compounds, cellulose derivatives, acrylamide polymers,polyvinyl pyrrolidone, polysaccharides such as dixtran, gum arabic andthe like.

The described photographic emulsions and other layers of a photographicelement employed in the practice of the invention can also contain otherdispersed polymerized vinyl compounds, particularly those which increasethe dimensional stability of photographic materials. Suitable syntheticpolymers include those described, for example, in U.S. Pat. Nos.3,142,568 of Nottorf, issued July 28, I964; 3,193,386 of White, issuedJuly 6, 1965; 3,062,674 of l-louck, Smith and Yudelson, issued Nov. 6,1962; 3,220,844 of Houck, Smith and Yudelson, issued Nov. 30, 1965;3,287,289 of Ream and Fowler, issued Nov. 22, 1966; and 3,411,9l1 ofDykstra; and include, for example, the water-insoluble polymers ofalkylacrylates and methylacrylates, acrylic acid, sulfoalkylacrylates ormethacrylates and the like.

While the photographic layer may be adhered to the support directly bythe carboxylated polyester subbing layer, it is usually desirable tointerpose a conventional gelatin-cellulose ester subbing layer, such asa gelatin-cellulose nitrate layer between the sensitized layer and thecarboxylated polyester layer. The amount of cellulose nitrate in thesubbing layer is generally between 25 and 75 percent by weight based onthe weight of gelatin and cellulose nitrate and is preferably about 50percent by weight. The layer is conveniently applied from an aqueoussolution of one or more organic solvents.

The carboxylated polyester is advantageously applied to a fully orientedpolyester support from solution in one or more organic solvents,desirably relatively nonflammable. Easily vaporized suitable solventsinclude ketonic solvents such as cyclohexanone, acetone, etc.; andhalogenated hydrocarbon solvents such as methylene chloride. Mixtures ofketonic solvents and halogenated hydrocarbon solvents are especiallyuseful. In a preferred embodiment the coating solution contains about toabout percent cyclohexanone and about 65 to 80 percent methylenechloride. In an especially advantageous embodiment of the presentinvention the coating solution also contains an adhesion promoting(attack) solvent. The selection of the adhesion promoter will normallydepend on the particular dianhydride modified polyester, the particularsolvent system, etc. utilized in any given system. Although resorcinolhas remarkable versatility in this respect, other hydroxyphenol solventsare considered to give satisfactory results. Examples of other solventsconsidered suitable include orcinol, catechol, pyrogallol, l-naphthol,2,4-dinitrophenol, 2,4,6-trinitrophenol, 4-chlororesorcinol,2,4dihydroxy toluene, 1,3-naphthalenediol, acrylic acid, the sodium saltof l-naphthol-4-sulfonic acid, benzyl alcohol, trichloroacetic acid,o-hydroxybenzotrifluoride, m-hydroxybenzotrifluoride, o-fluorophenol,m-fluorophenol, p-fluorophenol, chloral hydrate, and o-cresol. Mixturesof two or more adhesion promoters can be employed if desired. Theadhesion promoter usually comprises at least about 3 weight percent ofthe total solution, normally about 3 to about 10 weight percent,advantageously 5 to 8 percent.

The amount of carboxylated polyester in the coating solution is usuallyless than 25 weight percent based on the weight of the solution andpreferable from 0.5 to 2 weight percent. Thus, soluble polyestersaccording to the present invention are soluble in the selected solvent,e.g., methylene chloride, or desirably cyclohexanone-methylene chloridemixture, to at least 0.5 weight percent. The layer is coated on thepolyester substrate in conventional apparatus to a thickness sufficientto ensure a substantially complete coating overthe substrate. A thinlayer is preferable to minimize thickness and waste and, in general, thelayer is not more than 0.01 inches. The coated layer may be air dried atroom temperature or in heated air.

By providing a solvent soluble carboxylated polyester as described, itis possible to obtain excellent adhesion of gelatincontaining layers toa polyester support.

The invention has been described in detail with particular reference topreferred embodiments thereof, but it will be understood that variationsand modifications can be effected within the spirit and scope of theinvention.

We claim:

1. A photographic element comprising a polyester support, agelatin-cellulose ester photographic subbing layer, a gelatino-silverhalide emulsion layer on said gelatin-cellulose ester layer and anorganic solvent-soluble carboxylated polyester subbing layer bondingsaid gelatin-cellulose ester layer to said polyester support, saidcarboxylated polyester being the reaction product of an organic solventsoluble polyester and from 1 to about 15 mole percent of an organicdianhydride.

2. A photographic element according to claim 1 wherein said organicdianhydride is selected from the group consisting of pyromelliticdianhydride, 3,4,3',4'-benzophenonetetracarboxylic dianhydride,1,2,3,4-cyclopentanetetracarboxylic dianhydride and the dimaleicanhydride adduct of myrcene.

3 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No- 3 1Dated 25 1972 Inventor(s) Frederick J. Jacobv et al It is certified thaterror appears in the aboveidentified patent and that said Letters Patentare hereby corrected as shown below:

"1 In column 5, I line 15, delete "'ZbSH O and insert -2H O-- 2. Incolumn 5, line 31, delete "2b8H O" and insert --2H O-- 3. In column 7,line 26, following using, delete "30" 4. In column 7, line 54, following"250, delete and insert Signed and sealed this 12th day of September-1972.

(SEAL) Attest;

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents

2. A photographic element according to claim 1 wherein said organic dianhydride is selected from the group consisting of pyromellitic dianhydride, 3,4,3'',4''-benzophenonetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride and the dimaleic anhydride adduct of myrcene. 